Thermochemical study of the ortho interactions in alkyl substituted anilines

Verevkin, Sergey P.

doi:10.1006/jcht.1999.0587

Cited by 12 publications

(7 citation statements)

References 27 publications

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“…Further, the values based on the Gaussian-3 approach are in clear agreement with the experimental result due to Steele et al . and also with the estimates of Verevkin 7 Estimated Enthalpies of Formation for the Three Toluidines (methylanilines).…”

Section: Resultssupporting

confidence: 90%

“…For the other two isomers, namely, m - and p -methylaniline, the methyl group was assumed to rotate freely and rather different values of Δ f have been calculated; for the m -methylaniline, Δ f = 61.1 kJ·mol -1 , while for p -methylaniline Δ f = 41.8 kJ·mol -1 . In a more recent work, Verevkin reported the ortho interactions in alkyl substituted anilines . After analysis of data available in the literature noticed the large enthalpic difference between the experimental Δ f for the o -methylaniline compound and that reported in the NIST Webbook for the p -methylaniline compound since it was not expected as it seemed from the absence of an evident stabilization on going from o -methylaniline, to 2,4-dimethylaniline .…”

Section: Resultsmentioning

confidence: 99%

“…In a more recent work, Verevkin reported the ortho interactions in alkyl substituted anilines . After analysis of data available in the literature noticed the large enthalpic difference between the experimental Δ f for the o -methylaniline compound and that reported in the NIST Webbook for the p -methylaniline compound since it was not expected as it seemed from the absence of an evident stabilization on going from o -methylaniline, to 2,4-dimethylaniline . Based also on an empiric treatment of literature data, Verevkin proposed that a much more acceptable estimate for the gas-phase enthalpies of formation of both m - and p -methylanilines would be close to 55.0 kJ·mol -1 .…”

Section: Resultsmentioning

confidence: 99%

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Experimental and Computational Study of the Thermochemistry of the Fluoromethylaniline Isomers

2007

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The standard (po = 0.1 MPa) molar enthalpies of formation in the condensed phase of seven isomers of fluoromethylaniline were derived from the standard molar energies of combustion, in oxygen, to yield CO2(g), N2(g) and HF.10H2O(l), at T = 298.15 K, measured by rotating bomb combustion calorimetry. The standard molar enthalpies of vaporization or sublimation of these compounds, also at T = 298.15 K, were determined using Calvet microcalorimetry, while the enthalpies of fusion of the solid compounds were determined by differential scanning calorimetry. The standard molar enthalpies of formation in the gaseous phase, at T = 298.15 K, were derived from the former two experimental quantities. G3MP2//B3LYP calculations were performed for all possible fluoromethylanilines allowing the estimation of data for the isomers that were not studied experimentally. The Cox scheme was applied with two different approaches for the estimation of the standard molar enthalpies of formation of all the isomers studied, and this led to the conclusion that the literature values for the enthalpies of formation of the meta and para isomers of methylaniline seem to be not reliable. Further G3MP2//B3LYPs calculations on the methylaniline isomers yielded new values for the standard molar enthalpies of formation of the isomers of methylaniline, which have been tested under the Cox scheme, resulting in better estimates.

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Section: Resultssupporting

confidence: 90%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

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Experimental and Computational Study of the Thermochemistry of the Fluoromethylaniline Isomers

2007

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“…(a) Group additivity procedures are conventionally applied to derive substituent effects (or strain enthalpies) as the differences between the observed enthalpies of formation in the gaseous state and the values calculated by applying anyone of a number of group-additivity schemes. 40,41 We have discussed the substituent effects of alkyl-anilines recently 1,2 in such a (b) Isodesmic reactions involving aminotoluene can be also used to obtain the effects of the interaction of CH 3 and NH 2 by attaching them to the separate benzene rings (according to the scheme presented by reaction 2 above). This will allow the total substituent effect to be evaluated for each species studied.…”

Section: Resultsmentioning

confidence: 99%

“…In the course of our previous investigation of aliphatic , and aromatic amines, we have revealed that the thermochemical literature on the title compounds is in disarray. Indeed, Draeger reported the following gaseous enthalpies of formation, Δ f (g): 54.8, 61.1, and 41.8 kJ·mol -1 for 2-, 3-, and 4-aminotoluenes at 298.15 K. These values assume noticeable interactions (over 20 kJ·mol -1 ) between the methyl and amino group in aminotoluenes, which are dependent on their position on the benzene ring.…”

Section: Introductionmentioning

confidence: 99%

Enthalpies of Formation and Substituent Effects of ortho-, meta-, and para-Aminotoluenes from Thermochemical Measurements and from Ab Initio Calculations

Emel′yanenko

Verevkin

2005

J. Phys. Chem. A

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The molar enthalpies of vaporization of 2-amino-, 3-amino-, and 4-aminotoluenes were obtained from the temperature dependence of the vapor pressure measured by the transpiration method. The molar enthalpy of sublimation of 4-aminotoluene was measured in the same way. The standard (p(o) = 0.1 MPa) molar enthalpy of formation delta fH(o)m(cr) at the temperature T = 298.15 K of crystalline 4-aminotoluene was measured using combustion calorimetry. The thermochemical investigations of aminotoluenes available in the literature were collected and combined with our own experimental results to obtain our own reliable standard molar enthalpies of formation at T = 298.15 K in the gaseous state. Ab initio calculations of aminotoluenes have been performed using the MP2Full/6-31G(d) and G3(MP2) basis sets, and the results from the bond separation method are in excellent agreement with the experiment. These new results help to resolve the uncertainty in the available thermochemical data on aminotoluenes. Weak mutual interactions of substituents in aminotoluenes have been realized using an isodesmic reaction procedure.

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General and Theoretical Aspects of Anilines

Nguyen

2009

Patai's Chemistry of Functional Groups

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Thermochemical study of the ortho interactions in alkyl substituted anilines

Cited by 12 publications

References 27 publications

Experimental and Computational Study of the Thermochemistry of the Fluoromethylaniline Isomers

Experimental and Computational Study of the Thermochemistry of the Fluoromethylaniline Isomers

Enthalpies of Formation and Substituent Effects of ortho-, meta-, and para-Aminotoluenes from Thermochemical Measurements and from Ab Initio Calculations

General and Theoretical Aspects of Anilines

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